1. Field of the Invention
The invention relates, generally, to pressure regulators and, more specifically, to a pneumatic pressure regulator having an adjustable regulator piston.
2. Description of the Related Art
Pneumatic pressure regulators are well known in the art and are employed in numerous environments to regulate a pneumatic supply pressure to a predetermined system pressure. The controlled system pressure provided by the regulator is then used to operate the various pneumatically actuated devices within the system. The regulator acts to maintain a desired operating pressure and to eliminate supply pressure fluctuations. In this way, the regulator ensures that the active system devices will operate properly with reliable and repeatable actuations.
In application, there exists a wide variety of manufacturing and processing environments where a high pneumatic flow rate and very fast response time are desired. It is essential that accurately regulated pneumatic pressure be provided to the active devices in these environments. As the process technology in these production environments has advanced, there has been an increase in the demand for smaller and more accurate active pneumatic devices, and subsequently, for smaller and more accurate regulators to control the supply pressure. Additionally, to achieve greater control and accuracy, depending upon the specific application, a number of regulators may be used at various locations throughout the pneumatic system, even to the point of providing a separate regulator for each individual active device. In these circumstances, it is desirable to locate the regulators in very close proximity to the active devices. This, in turn, places the regulators extremely close to the manufacturing or processing events, which requires that the regulators be installed in tight spaces with even smaller dimensions.
Known pressure regulators utilizing a diaphragm to control output pressure are generally too large to be utilized in these environments. This is one factor that has driven the ongoing improvements and advances in piston-controlled regulators. Regulators of this type typically use a piston movably supported within a bore. The piston is responsive to regulate the downstream pressure acting upon it. The piston may be operatively connected to or associated with a poppet control valve, so that as the piston moves in response to the downstream pressure. More specifically, when the downstream pressure exceeds a desired maximum, control and thereby regulation is subsequently effected to regulate the input pressure to a desired output pressure.
Generally speaking, pistoned regulators are better suited for use in the tight confines of the above-mentioned operating environments than diaphragm operated regulators of the type commonly known in the art. However, in the past, certain design barriers have limited the extent to which the piston size, and therefore the regulator itself, could be reduced. When the active surface area of the piston is reduced below a predetermined amount, accurate pressure control may be lost. To counter this, larger, piston controlled pressure regulators presently known in the related art may be employed remotely from the remainder of the pneumatically actuated system. Thus, these larger, remotely disposed regulators suffer the continuing requirement that they must be interconnected via conduits or other flow passages, which require additional hardware and plumbing, and can lower pneumatic efficiencies and introduce line losses within the system.
While the use of larger, remotely disposed regulators has generally worked well in the past, there remains an ongoing need in the art to simplify pneumatic systems and thereby lower costs of manufacture and/or assembly by creating ever smaller, yet highly accurate, piston controlled pressure regulators. Smaller regulators can be located in very close proximity to active system components, thereby shortening flow paths, reducing or eliminating additional plumbing and hardware, and increasing pneumatic flow efficiency. The solutions to these problems that have been proposed in the related art have failed to overcome the problems created when the active surface area of the piston falls below a minimal piston size in an attempt to achieve the desired regulator size criteria.
The present invention overcomes the disadvantages of the related art in a pneumatic pressure regulator assembly. The pneumatic pressure regulator assembly includes a regulator housing having an inlet adapted for fluid communication with a supply of pneumatic pressure at a first elevated pressure, at least one outlet adapted to provide pneumatic pressure to at least one downstream pneumatically actuated device at a second, lower regulated pressure and a regulator valve assembly. The regulator valve assembly has a valve member movably supported within the regulator housing between an open position and a closed position. A piston assembly is movably supported in the regulator housing and acts to bias the valve member to its open position when the downstream pressure flowing through the outlet is below a predetermined value. The piston assembly includes a pressure responsive surface defining a geometric shape having a major axis and a minor axis wherein the major axis is greater than the minor axis. The piston assembly is responsive to pneumatic pressure flowing between the inlet and outlet to reduce the biasing force acting on the valve member such that the valve member moves to its closed position when the downstream pressure flowing through the outlet exceeds a predetermined value.
One advantage of the present invention is that it provides an accurate and highly responsive pressure regulator, which can be constructed of a smaller size than has been previously attainable in the conventional art. More specifically, the width of the pressure regulator of the present invention may be reduced as compared to known regulators in the related art such that it is relatively thin while still providing sufficient surface area to the piston such that the regulator maintains its responsiveness.
Another advantage of the present invention is that by providing a pressure regulator of much smaller size, the present invention can be installed on, or in close proximity to, the device being regulated such that the flow paths therebetween are shortened and the number of related hardware components are reduced. This simplifies the design of pneumatically actuated systems, which leads to reduced costs, increased efficiency and convenience.